Sidewalk Science: Lifetime hair and fingernail growth

 How much do human hair and fingernails grow over a lifetime?

 02/23/24

• Sidewalk science

• Hair grows about 6 inches a year Fingernails grow about 2 inches a year.
  

• The following shows lifetime growth for an 85 year (low, average, high)

Sidewalk Writing

Hair and Nail Lifetime Growth Length Graphic to Scale based on the below

• Hair lifetime growth - length ranges from for low, average, high are: 20ft, 40ft, 80ft
• Fingernail lifetime growth - length ranges from for low, average, high are: 10ft, 15ft, 20ft

Resources

• Hair

• https://www.kiehls.com/skincare-advice/how-fast-does-hair-grow.html#:~:text=We'll%20cut%20straight%20to,from%20which%20new%20hair%20grows. - We’ll cut straight to it: On average, hair grows at a rate of about half an inch per month, or six inches per year.

• Google Gemini - ¼ to 1 inch per month.  

• Fingernails

• Google Gemini 1/32 to 1/16 per week or ⅛ to ¼ per month

• Or .125 to .25 inches per month

• https://christopherstephens.com/blogs/news/the-hair-raising-statistics#:~:text=Fingernails%20grow%20approximately%201%2F8,to%206%20inches%20per%20year. - In humans, fingernails grow at an average rate of approx. 3.5 mm (0.14 in) a month, whereas toenails grow about half as fast (approx. average 1.6 mm (0.063 in) a month).

• Your fingernails grow at an average rateTrusted Source of 3.47 millimeters (mm) per month, (.14 inches)

• https://www.arkansasonline.com/news/2019/mar/18/fingernails-growing-while-you-read-this/ - ​​Fingernails grow at 0.02 inches per week, four times faster than toenails. (.08 inches per month)